1. Field of the Invention
The present invention generally relates to a touch panel, and more particularly to a touch panel capable of preventing electrically shorting traces by residual electrode material.
2. Description of Related Art
A touch screen is an input/output device that adopts sensing technology and display technology, and has been widely employed in electronic devices such as portable or hand-held electronic devices.
A capacitor-based touch panel is a commonly used touch panel that utilizes capacitive coupling effect to detect touch position. Specifically, capacitance corresponding to the touch position changes and is thus detected, when a finger touches a surface of the touch panel.
FIG. 1 shows a top view of a touch panel 100 having electrodes formed on a centrally-located transparent touch area 11. The touch panel 100 also has non-transparent conductive traces formed on a trace area 12 being located on periphery of the touch panel 100 and surrounding the touch area 11. The traces are used to transmit signals between a controller (not shown) and the electrodes.
Ideally, the electrodes should be formed only on the centrally-located touch area 11 of the touch panel 100. In practice, some conductive material of the electrodes may reside on peripherally-located trace area 12. In case that the residual conductive material is not removed, the residual conductive material may electrically short traces that are formed later on the trace area 12.
A need has thus arisen to propose a novel touch panel that is capable of preventing electrically shorting traces by electrode conductive material resided on the trace area 12.